Jts ct ruby specs

spec/blocks_spec.rb

@@ -0,0 +1,73 @@
+# frozen_string_literal: true
+
+require 'minitest/autorun'
+require 'open3'
+
+# rubocop:disable Metrics/BlockLength
+
+describe 'Blocks' do
+  describe 'an empty block' do
+    it 'renders with one space' do
+      assert_equal_and_valid(
+        'loop {}',
+        'loop { }'
+      )
+    end
+  end
+
+  describe 'a block with a paramer and a body' do
+    it 'inserts a space arount the content and paramter' do
+      assert_equal_and_valid(
+        'loop {|el|el + 1}',
+        'loop { |el| el + 1 }'
+      )
+    end
+  end
+
+  describe 'a block with no parameter and a body' do
+    it 'surrounds the block content with one space' do
+      assert_equal_and_valid(
+        'loop {   true}',
+        'loop { true }'
+      )
+    end
+  end
+
+  describe 'a block with a parameter and no body' do
+    it 'inserts one space around the parameter' do
+      assert_equal_and_valid(
+        'loop {|el|   }',
+        'loop { |el| }'
+      )
+    end
+  end
+
+  def assert_equal_and_valid(input, expected)
+    result = apply_prettier(input)
+    assert_equal expected, result
+    ensure_valid(expected)
+  end
+
+  def ensure_valid(string)
+    _, stderr_str, status = Open3.capture3('ruby -c', stdin_data: string)
+    assert_equal status.success?, true, stderr_str
+  end
+
+  def apply_prettier(string)
+    file = write_string_to_tempfile(string)
+    run_prettier_on_file(file.path)
+  end
+
+  def write_string_to_tempfile(string)
+    Tempfile.new('prettier-ruby-test.rb').tap do |file|
+      file.write(string)
+      file.close
+    end
+  end
+
+  def run_prettier_on_file(path)
+    `bin/print #{path}`.rstrip
+  end
+end
+
+# rubocop:enable Metrics/BlockLength

src/nodes/blocks.js

@@ -110,11 +110,14 @@ const printBlock = (path, opts, print) => {
     return concat([breakParent, doBlock]);
   }
 
+  const blockContents = statements.body[0].body;
+  const blockContentsEmpty = blockContents.length === 0;
+
   const braceBlock = concat([
     " { ",
     variables ? path.call(print, "body", 0) : "",
     path.call(print, "body", 1),
-    " }"
+    blockContentsEmpty ? "}" : " }"
   ]);
 
   return group(ifBreak(doBlock, braceBlock));

test/cases/__snapshots__/blocks.test.js.snap

@@ -39,6 +39,8 @@ end
 
 loop { super_super_super_super_super_super_super_super_super_super_super_long }
 
+loop { |i| }
+
 loop { |i| 1 }
 
 loop { |i; j| 1 }

test/cases/blocks.rb

@@ -42,6 +42,8 @@
   super_super_super_super_super_super_super_super_super_super_super_long
 end
 
+loop { |i| }
+
 loop { |i| 1 }
 
 loop { |i; j| 1 }